_screen calls non-existent program

[Sebastian Stark <seb-zsh@xxxxxxxxxxx>]

I just noticed that if I try screens completion I am not able to select one of many running sessions:

 screen -S <tab>

gives an empty set.

Looking at _screen I see that the list of existing sessions should come from

  _call_program screen-sessions $words[1] -ls

Now I'm wondering what the screen-sessions command should look like, it is not available on any of my machines. To me it looks a bit like it is the same as screen itself, because of the -ls option. But than I don't get the $words[1] part.

Any pointers?


Sebastian